atomic number 9
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A scientist points to the symbol for atomic number 9 on a large periodic table.
Definition
- Noun:
- A chemical element: "atomic number 9" is the scientific term for the chemical element with the number 9 in the periodic table. It is a highly reactive, pale yellow gas at room temperature.
- A specific element: It refers exclusively to the element fluorine.
Usage
- The term "atomic number 9" is used primarily in scientific, technical, and educational contexts to identify the element fluorine by its fundamental property—the number of protons in its nucleus.
- It is a precise identifier, often used in chemistry and physics to avoid ambiguity.
Examples
- Noun:
- The periodic table lists fluorine as atomic number 9.
- Atomic number 9 is essential for the production of many pharmaceuticals.
Advanced Usage
- In compound identification: While "atomic number 9" itself is not used in compounds, the element it denotes (fluorine) is a key component. For example, in discussing fluorocarbons, one might reference that they contain the element with atomic number 9.
- In nuclear contexts: The stability of an isotope can be discussed in relation to its atomic number; for instance, the only stable isotope of atomic number 9 is fluorine-19.
Variants and Related Words
- Fluorine (F): The common name for the element represented by atomic number 9.
- Fluorine is added to drinking water to prevent tooth decay.
- Fluoride: A compound containing fluorine, often referring to the anion (F⁻).
- Sodium fluoride is a common ingredient in toothpaste.
Synonyms
- Fluorine: The direct and most common synonym.
- F: The chemical symbol for the element.
Related Phrases
- Element 9: An informal, synonymous phrase.
- Element 9 is the lightest halogen.
- Group 17, Period 2: Its location in the periodic table, often mentioned alongside its atomic number for full classification.
A scientist points to the symbol for atomic number 9 on a large periodic table.
Noun
- a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite